Here’s why NASA’s Mars rovers are banned from investigating that liquid water

10/01/2015

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This week, NASA scientists announced that they had found
chemical evidence of liquid water on the surface of Mars. While they make a
compelling case, the existence of seasonal rivers of briney water will never be
100 percent confirmed until we can see it and touch it and analyse it, and if
it’s not actual humans on Mars doing that, we’ll have to study it vicariously
through our far-flung robots. Except we can’t. Not as long as those far-flung
robots originated on Earth, anyway. Right now, NASA’s Curiosity rover is about
50 kilometres from the site that scientists suspect holds liquid Martian water,
but thanks to an international treaty signed in 1967, it’s not allowed to go
anywhere near it.

This is because to get where it is on the surface of Mars,
Curiosity had to travel 225 million kilometres from Earth through space, and
along the way it could have picked up dirt and dust and all kinds of mysterious
microbes that make it far from sterile. As Marcus Strom points out at TheSydney Morning Herald, "That's a long way to go without having the right
sort of shower." Gross, Curiosity. Just go stand over there, will you? No,
no, keep going, further. Yep, keep going. Okay that's good, thank you!

And while scientists do their best to sterilise their
space-faring equipment once it arrives at its destination via what Swinburne
University astronomer Alan Duffy describes as "a very intense ultraviolet
tanning salon", if they can’t guarantee sterilisation, there’s no going
near that water.

"Because liquid water appears to be present ... we have
to take extra precautions to prevent contamination by Earth life," Rich
Zurek, the chief scientist for NASA’s Mars program, explained during a Reddit
AMA yesterday. "Our current rovers have not been sterilised to the degree
needed to go to an area where liquid water may be present."

As Akshat Rathi writes for Quartz, every country on Earth is
bound by the stipulations of the 1967 Outer Space Treaty, which forbids
"anyone from sending a mission, robot or human, close to a water source in
the fear of contaminating it with life from Earth".

Not that NASA couldn't sterilise the crap out of its rovers if
it wanted to. As UNSW astrobiologist Malcolm Walter told The Sydney Morning
Herald, they could blast Curiosity with crazy amounts of heat and radiation
that would wipe out anything and everything that managed to survive the journey
from Earth without a shadow of a doubt, but then they'd be wiping out the rover's
internal electronics in the process. Not exactly practical.

"In order to be completely sterile, they'd have to use
really powerful ionising radiation or heat, both of which would damage the
electronics," says Walter. "So they go as far as they dare."

What's the solution? We all know that NASA is planning on
sending humans to Mars for the first time in mid-2030, so maybe some lucky
astronauts will get to see liquid Martian water with their own eyes. Another
option would be to send robots to Mars that are capable of building other
robots that can investigate that water with little risk of contamination. Last
year, NASA announced that it's developing robots that can 3D-print
infrastructure on Mars, so this could well be a possibility.

Until then, Curiosity and its rover buddy Opportunity will
just have to revel in the ambigious state of their cleanliness, and stay the
hell away from the water.